1. Field of the Invention
This invention relates to a system and method for a high resolution, fully addressable volumetric display using a planar array.
2. Brief Description of the Prior Act
It has been known in the prior art to modulate or scan a beam, such as a laser beam, and then to project the scanned beam onto a screen. Examples of such systems are set forth in the Brief Description of the Prior Art in Garcia, Jr. et al. U.S. Pat. No. 5,042,909 and as well as in that patent. The prior art listed hereinbelow is incorporated herein by reference.
Such autostereoscopic volumetric display systems and methods have been described in the prior art and include a vertical planar screen rotated about a vertical axis, a first mirror located away from the vertical axis facing and below the screen which is also rotated with the screen about the same vertical axis and a second mirror located on the same rotational vertical axis, rotated with the screen and the first mirror and tilted so that an image projected parallel to the vertical axis is reflected from the second mirror to the first mirror and from the first mirror to the screen. The disclosures in the patents to Solomon (U.S. Pat. No. 4,983,031), Garcia (U.S. Pat. No. 5,042,909) and Botchko (U.S. Pat. No. 5,148,310) are exemplary of such prior art. Methods of generating such images using one or more scanned serial light sources are also described in the prior art as exemplified by the disclosures in the above mentioned Garcia and Botchko patents. Transformations are further described which translate a serial light beam input into flat images which are subsequently projected onto various display surfaces, this being exemplified in the disclosures of each of the above-mentioned patents.
Image sources described in the prior art comprise serial light sources where a light beam is cut into slices and projected onto the display. This limits the ability of the prior art to generate an image with resolution sufficiently high to be useful or to place a sufficient number of points of light simultaneously onto the display screen. The term "simultaneously" is defined herein as--appearing to the viewer to be simultaneous--even though the points of light are not initially generated simultaneously in time. Defects inherent in the prior art as described hereinabove include distortion, focus and image rotation errors.
The prior art also describes gas ion laser image sources which cannot generate full color images. Generating any color other than red, green or blue requires illuminating the same physical location simultaneously with more than one laser (in the case of a multicolor system including colors other than the primary colors). For example, a yellow point requires both a red and a green laser. To accomplish this, first, multiple lasers must be very precisely aligned to generate a single point. Voltage controlled oscillators or scanners suffer from both non-linearities of positioning and electrical drift. This, in essence, prevents the perfect alignment of multiple image sources which is necessary to generate nonprimary colors. Second, using two or more points of laser light to generate one viewable spot significantly reduces the number of points of light available to form an image, further reducing the resolution of the display.
One well known problem with volumetric displays is selection of the viewing perspective from which to display text and other two-dimensional symbology or icons. Although the volumetric image may be both viewable and useful from all aspect angles, it is impossible to pre-select the position of the viewer. Furthermore, doing so would obviate the usefulness of a volumetric display which can be viewed from all sides. This problem is not addressed by the prior art.